Semiconductor device structure with high voltage device

A semiconductor device structure, comprising:

• a semiconductor substrate having a high-voltage device region and a low-voltage device region;
• a first well region in the high-voltage device region, wherein the first well region surrounds sides and bottoms of a drain region and a source region;
• a second well region in the low-voltage device region and adjacent to the second well region, wherein the second well region has a conductivity type opposite to that of the first well region;
• a conductor electrically connected to the drain region and extending across an interface between the first well region and the second well region;
• and
• a shielding element ring between the conductor and the semiconductor substrate, wherein the shielding element ring covers the interface between the first well region and the second well region.

A semiconductor device structure, comprising:

• a high-voltage transistor including:
• a source region in a first well region within a second well region;
• and
• a drain region in the second well region;
• a low-voltage device including a doped region, wherein the doped region has a conductivity type opposite to that of the second well region, and the doped region is adjacent to the second well region;
• a conductor electrically connected to the high-voltage transistor and extending across an interface between the doped region of the low-voltage device and the second well region of the high-voltage transistor;
• and
• a shielding element ring between the conductor and the doped region, wherein the shielding element ring extends over and across the interface.